# Changelog
## v1.3.1
### Bug fixes
- Event Handler not calling `init/1` callback function on restart ([#463](https://github.com/commanded/commanded/pull/463)).
- Call process manager `init/1` function on process restart ([#464](https://github.com/commanded/commanded/pull/464)).
## v1.3.0
### Enhancements
- Allow command identity to be provided during dispatch ([#406](https://github.com/commanded/commanded/pull/406)).
- Define `Commanded.Telemetry` module to emit consistent telemetry events ([#414](https://github.com/commanded/commanded/pull/414)).
- Telemetry `[:commanded, :aggregate, :execute]` events ([#407](https://github.com/commanded/commanded/pull/407)).
- Telemetry `[:commanded, :event, :handle]` events ([#408](https://github.com/commanded/commanded/pull/408)).
- Telemetry `[:commanded, :process_manager, :handle]` events ([#418](https://github.com/commanded/commanded/pull/418)).
- Telemetry `[:commanded, :application, :dispatch]` ([#423](https://github.com/commanded/commanded/pull/423)).
- Graceful shutdown of event handlers ([#431](https://github.com/commanded/commanded/pull/431)).
- Ensure command dispatch metadata is a map ([#432](https://github.com/commanded/commanded/pull/432)).
- Retry command execution on node down ([#429](https://github.com/commanded/commanded/pull/429)).
- Dispatch returning resultant events ([#444](https://github.com/commanded/commanded/pull/444)).
- Get aggregate state ([#448](https://github.com/commanded/commanded/pull/448)).
- Support telemetry v1.0 ([#456](https://github.com/commanded/commanded/pull/456)).
## v1.2.0
### Enhancements
- Add `init/1` callback function to event handlers and process managers ([#393](https://github.com/commanded/commanded/pull/393)).
- Include `application` and `handler_name` as additional event handler metadata ([#396](https://github.com/commanded/commanded/pull/396)).
- Allow `GenServer` start options to be provided when starting event handlers and process managers ([#398](https://github.com/commanded/commanded/pull/398)).
- Add `hibernate_after` option to application config ([#399](https://github.com/commanded/commanded/pull/399)).
- Add support for providing adapter-specific event store subscription options ([#391](https://github.com/commanded/commanded/pull/391)).
- Support custom state for event handlers ([#400](https://github.com/commanded/commanded/pull/400)).
- Allow event handlers and process manager `error` callback to return failure context struct ([#397](https://github.com/commanded/commanded/issues/397)).
- Allow a before execute function to be defined which is called with the command dispatch execution context and aggregate state before ([#402](https://github.com/commanded/commanded/pull/402)).
### Bug fixes
- Allow process manager `error/3` callback to return `:skip` for failed commands, not just failed events ([#362](https://github.com/commanded/commanded/issues/362)).
---
## v1.1.1
### Enhancements
- Capture exception on Process Manager `apply/2` and call `error/3` callback functions ([#380](https://github.com/commanded/commanded/pull/380)).
- Include metadata in upcaster protocol ([#389](https://github.com/commanded/commanded/pull/389)).
### Bug fixes
- Fix `Commanded.Aggregate.Multi.execute/2` calls which return ` Multi` struct ([#385](https://github.com/commanded/commanded/pull/385])).
## v1.1.0
### Enhancements
- Dynamic Commanded applications ([#324](https://github.com/commanded/commanded/pull/324)).
- Log and ignore unexpected messages received by event handlers and process manager instances ([#333](https://github.com/commanded/commanded/pull/333))
- Process manager `identity/0` function ([#334](https://github.com/commanded/commanded/pull/334)).
- Extend `Commanded.AggregateCase` ExUnit case template to support `Commanded.Aggregate.Multi`.
- Allow `Commanded.Aggregate.Multi` to return events as `:ok` tagged tuples.
- Run the formatter in CI ([#341](https://github.com/commanded/commanded/pull/341)).
- Add stacktraces to EventHandler error logging ([#340](https://github.com/commanded/commanded/pull/340))
- `refute_receive_event/4` only tests newly created events ([#347](https://github.com/commanded/commanded/pull/347)).
- Allow Commanded Application name to be set dynamically in middleware ([#352](https://github.com/commanded/commanded/pull/352)).
- Remove router module compile-time checking ([#363](https://github.com/commanded/commanded/pull/363)).
- Reduce memory consumption during aggregate state rebuild ([#368](https://github.com/commanded/commanded/pull/368)).
- Upgrade to `phoenix_pubsub` to 2.0 ([#365](https://github.com/commanded/commanded/pull/365)).
- Ignore `:not_found` error when reseting InMemory event store ([#354](https://github.com/commanded/commanded/pull/354)).
- Add `router/1` to `locals_without_parens` in Mix format config ([#351](https://github.com/commanded/commanded/pull/351)).
- Include stacktrace in event handler and process manager `error` callback functions ([#342](https://github.com/commanded/commanded/pull/342)).
- Call event handler's `error/3` callback function when `handle/2` function returns an invalid value ([#372](https://github.com/commanded/commanded/pull/372)).
### Bug fixes
- Fixes the typespec for command dispatch ([#325](https://github.com/commanded/commanded/pull/325)).
- Process manager stops if `interested?/1` returns an empty list ([#335](https://github.com/commanded/commanded/pull/335)).
---
## v1.0.1
### Enhancements
- Global registry using Erlang's `:global` module ([#344](https://github.com/commanded/commanded/pull/344)).
- Command dispatch return ([#331](https://github.com/commanded/commanded/pull/331)).
### Bug fixes
- Fix distributed subscription registration bug ([#345](https://github.com/commanded/commanded/pull/345)).
- Retry event handler and process manager subscriptions on error ([#348](https://github.com/commanded/commanded/pull/348)).
## v1.0.0
### Breaking changes
- Support multiple Commanded apps ([#298](https://github.com/commanded/commanded/pull/298)).
### Enhancements
- Define adapter behaviour modules for event store, pubsub, and registry ([#311](https://github.com/commanded/commanded/pull/311)).
- Add `AggregateCase` ExUnit case template to support aggregate unit testing ([#315](https://github.com/commanded/commanded/pull/315)).
- Application config lookup ([#318](https://github.com/commanded/commanded/pull/318)).
### Bug fixes
- Fix process manager exception on start ([#307](https://github.com/commanded/commanded/pull/307)).
- Fix commanded aggregate race ([#308](https://github.com/commanded/commanded/pull/308)).
- Fix Dialyzer warnings and include in Travis CI ([#317](https://github.com/commanded/commanded/pull/317)).
### Upgrading
[Follow the upgrade guide](https://hexdocs.pm/commanded/1.0.0/0.19-1.0.html) to define and use your own Commanded application.
---
## v0.19.1
### Enhancements
- Reset event handler mix task `mix commanded.reset MyApp.Handler` ([#293](https://github.com/commanded/commanded/pull/293)).
### Bug fixes
- Fix regression in `Commanded.Middleware.Logger.delta` ([#295](https://github.com/commanded/commanded/pull/295)).
## v0.19.0
### Enhancements
- Update typespec for `data` and `metadata` fields in `Commanded.EventStore.EventData` struct ([#246](https://github.com/commanded/commanded/pull/246)).
- Add `include_execution_result` and `aggregate_version` to typespec for router command dispatch ([#262](https://github.com/commanded/commanded/pull/262)).
- Add `.formatter.exs` to Hex package ([#247](https://github.com/commanded/commanded/pull/247)).
- Event upcasting ([#263](https://github.com/commanded/commanded/pull/263)).
- Support `:ok` tagged tuple events from aggregate ([#268](https://github.com/commanded/commanded/pull/268)).
- Modify `Commanded.Registration.start_child` to pass a child_spec ([#273](https://github.com/commanded/commanded/pull/273)).
- Add `supervisor_child_spec/2` to `Commanded.Registration` behaviour ([#277](https://github.com/commanded/commanded/pull/277)) used by [Commanded Horde Registry](https://github.com/uberbrodt/commanded_horde_registry).
- Ensure Commanded can be compiled when optional Jason dependency is not present ([#286](https://github.com/commanded/commanded/pull/286)).
- Fix Aggregate initialization races ([#287](https://github.com/commanded/commanded/pull/287)).
- Support `{:system, varname}` format in Phoenix PubSub config ([#291](https://github.com/commanded/commanded/pull/291)).
### Breaking changes
- Use `DateTime` instead of `NaiveDateTime` for all datetimes ([#254](https://github.com/commanded/commanded/pull/254)).
This affects the `created_at` field defined in the `Commanded.EventStore.RecordedEvent`. You will need to migrate from `NaiveDateTime` to `DateTime` if you use this field in your code (such as in an event handler's metadata).
---
## v0.18.1
### Enhancements
- Process manager idle process timeout ([#290](https://github.com/commanded/commanded/pull/290)).
- Register event handler and process manager subscriptions on process start ([#272](https://github.com/commanded/commanded/pull/272)).
## v0.18.0
### Enhancements
- Rename `uuid` dependency to `elixir_uuid` ([#178](https://github.com/commanded/commanded/pull/178)).
- Allow aggregate identity to be of any type that implements the `String.Chars` protocol ([#166](https://github.com/commanded/commanded/pull/166)).
- Process manager and event handler error & exception handling ([#192](https://github.com/commanded/commanded/pull/192)).
- Process manager event handling timeout ([#193](https://github.com/commanded/commanded/pull/193)).
- Allow event handlers to subscribe to individual streams ([#203](https://github.com/commanded/commanded/pull/203)).
- Add new values for `expected_version` for event store append events behaviour ([#127](https://github.com/commanded/commanded/pull/127)).
- Export `Commanded.Commands.Router` macros in `.formatter.exs` file ([#204](https://github.com/commanded/commanded/pull/204)).
- Generate specs and docs for Router dispatch functions only once ([#206](https://github.com/commanded/commanded/pull/206)).
- Allow two-arity predicate function in `wait_for_event` receiving both event data and recorded event struct ([#213](https://github.com/commanded/commanded/pull/213)).
- Allow `:infinity` timeout on command dispatch ([#227](https://github.com/commanded/commanded/pull/227))
- Strict process manager routing ([#243](https://github.com/commanded/commanded/pull/243)).
- Allow `Commanded.Aggregate.Multi` to be nested ([#244](https://github.com/commanded/commanded/pull/244)).
- Add `child_spec/0` function to `Commanded.EventStore` behaviour.
- Add `delete_subscription/2` to `Commanded.EventStore` behaviour ([#245](https://github.com/commanded/commanded/pull/245)).
- Add `refute_receive_event/2` to `Commanded.Assertions.EventAssertions` test helpers.
### Bug fixes
- Fix typo in `include_execution_result` global router option ([#216](https://github.com/commanded/commanded/pull/216)).
- Handle the `{:ok, _}` tuple dispatch result in process manager command dispatch ([#236](https://github.com/commanded/commanded/pull/236)).
- Allow string keys for `Commanded.Middleware.Pipeline.assign_metadata/3`, atoms are being deprecated ([#228](https://github.com/commanded/commanded/pull/228))
- Fix `Commanded.PubSub.subscribe` typespec ([#222](https://github.com/commanded/commanded/pull/222)).
### Breaking changes
- Migrate to [Jason](https://hex.pm/packages/jason) for JSON serialization ([#234](https://github.com/commanded/commanded/pull/234)).
You will need to add Jason as a dependency in `mix.exs`:
```elixir
defp deps do
[{:jason, "~> 1.2"}]
end
```
Jason has _no support_ for encoding arbitrary structs - explicit implementation of the `Jason.Encoder` protocol is always required. You *must* update all your domain event modules, aggregate state (when using state snapshotting), and process manager state to include `@derive Jason.Encoder` as shown below:
```elixir
defmodule AnEvent do
@derive Jason.Encoder
defstruct [:field]
end
```
- Extend aggregate lifespan behaviour to include `after_error/1` and `after_command/1` callbacks ([#210](https://github.com/commanded/commanded/pull/210)).
Previously you only had to define an `after_event/1` callback function to implement the `Commanded.Aggregates.AggregateLifespan` behaviour:
```elixir
defmodule BankAccountLifespan do
@behaviour Commanded.Aggregates.AggregateLifespan
def after_event(%BankAccountClosed{}), do: :stop
def after_event(_event), do: :infinity
end
```
Now you must also define `after_command/1` and `after_error/1` callback functions:
```elixir
defmodule BankAccountLifespan do
@behaviour Commanded.Aggregates.AggregateLifespan
def after_event(%BankAccountClosed{}), do: :stop
def after_event(_event), do: :infinity
def after_command(%CloseAccount{}), do: :stop
def after_command(_command), do: :infinity
def after_error(:invalid_initial_balance), do: :stop
def after_error(_error), do: :stop
end
```
### Upgrading
Please ensure you upgrade the following event store dependencies.
Using the Elixir [EventStore](https://github.com/commanded/eventstore):
- `eventstore` to [v0.16.0](https://hex.pm/packages/eventstore)
- `commanded_eventstore_adapter` to [v0.5.0](https://hex.pm/packages/commanded_eventstore_adapter)
Using Greg Young's [Event Store](https://eventstore.org/):
- `commanded_extreme_adapter` to [v0.6.0](https://hex.pm/packages/commanded_extreme_adapter)
Commanded Ecto projections:
- `commanded_ecto_projections` to [v0.8.0](https://hex.pm/packages/commanded_ecto_projections)
Commanded scheduler:
- `commanded_scheduler` to [v0.2.0](https://hex.pm/packages/commanded_scheduler)
---
## v0.17.5
### Enhancements
- Process manager idle process timeout ([#290](https://github.com/commanded/commanded/pull/290)).
## v0.17.4
### Bug fixes
- Register event handler and process manager subscriptions on process start ([#272](https://github.com/commanded/commanded/pull/272)).
## v0.17.3
### Bug fixes
- Fix snapshot recording ([#196](https://github.com/commanded/commanded/pull/196)).
- Fixed warning about deprecated time unit in elixir 1.8 ([#239](https://github.com/commanded/commanded/pull/239)).
## v0.17.2
### Enhancements
- Remove default `error/4` callback function from process manager to silence deprecation warning.
## v0.17.1
### Enhancements
- Support `Phoenix.PubSub` v1.1.0.
### Bug fixes
- Set default aggregate lifespan timeout to `:infinity` ([#200](https://github.com/commanded/commanded/pull/200)).
## v0.17.0
### Enhancements
- Ability to globally override `include_execution_result` and `include_aggregate_version` in environment config ([#168](https://github.com/commanded/commanded/pull/168)).
- Handle custom type serialization in snapshot source type ([#165](https://github.com/commanded/commanded/pull/165)).
- Fix compiler warnings in generated code (routers, event handlers, and process managers).
- Add `InMemory.reset!/0` for testing purposes ([#175](https://github.com/commanded/commanded/pull/175)).
### Bug fixes
- Ensure process managers can be configured with `:strong` consistency.
- Fix error when subscription process already tracked ([#180](https://github.com/commanded/commanded/pull/180)).
---
## v0.16.0
- Support composite command routers ([#111](https://github.com/commanded/commanded/pull/111)).
- Aggregate state snapshots ([#121](https://github.com/commanded/commanded/pull/121)).
- New `error/3` callback for process manager and deprecated `error/4` ([#124](https://github.com/commanded/commanded/pull/124))
- Router support for identity prefix function.
- Retry command execution on concurrency error ([#132](https://github.com/commanded/commanded/pull/132)).
- Event handler `error/3` callback ([#133](https://github.com/commanded/commanded/pull/133)).
- Support distributed dispatch consistency ([#135](https://github.com/commanded/commanded/pull/135)).
- Defer event handler and process router init until after subscribed ([#138](https://github.com/commanded/commanded/pull/138)).
- Replace aggregate lifespan `after_command/1` callback with `after_event/1` ([#139](https://github.com/commanded/commanded/issues/139)).
- Support process manager routing to multiple instances ([#141](https://github.com/commanded/commanded/pull/141)).
- Allow a default consistency to be set via the application env ([#150](https://github.com/commanded/commanded/pull/150)).
- Command dispatch consistency using explicit handler names ([#161](https://github.com/commanded/commanded/pull/161)).
### Breaking changes
- The `Commanded.Aggregates.AggregateLifespan` behaviour has been changed from `after_command/1` to `after_event/1`. You will need to update your own lifespan modules to use events instead of commands to shutdown an aggregate process after an inactivity timeout.
### Upgrading
Please ensure you upgrade the following event store dependencies.
Using the Elixir [EventStore](https://github.com/commanded/eventstore):
- `eventstore` to [v0.14.0](https://hex.pm/packages/eventstore)
- `commanded_eventstore_adapter` to [v0.4.0](https://hex.pm/packages/commanded_eventstore_adapter)
Using Greg Young's [Event Store](https://eventstore.org/):
- `commanded_extreme_adapter` to [v0.5.0](https://hex.pm/packages/commanded_extreme_adapter)
---
## v0.15.1
### Bug fixes
- Event handler `child_spec/1` must include config options defined by use macro.
## v0.15.0
### Enhancements
- Process manager command dispatch error handling ([#93](https://github.com/commanded/commanded/issues/93)).
- Event handlers may define an `init/0` callback function to start any related processes. It must return `:ok`, otherwise the handler process will be stopped.
- Add `include_execution_result` option to command dispatch ([#96](https://github.com/commanded/commanded/pull/96)).
- Add `Commanded.Aggregate.Multi` ([#98](https://github.com/commanded/commanded/pull/98)) as a way to return multiple events from a command dispatch that require aggregate state to be updated after each event.
- Correlation and causation ids ([#105](https://github.com/commanded/commanded/pull/105)).
- Initial support for running on a cluster of nodes ([#80](https://github.com/commanded/commanded/pull/80)).
### Bug fixes
- Adding a prefix to the aggregate in the router breaks the strong consistency of command dispatch ([#101](https://github.com/commanded/commanded/issues/101)).
### Upgrading
Please ensure you upgrade the following event store dependencies.
Using the Elixir [EventStore](https://github.com/commanded/eventstore):
- `eventstore` to [v0.13.0](https://hex.pm/packages/eventstore)
- `commanded_eventstore_adapter` to [v0.3.0](https://hex.pm/packages/commanded_eventstore_adapter)
Using Greg's [Event Store](https://eventstore.org/):
- `commanded_extreme_adapter` to [v0.4.0](https://hex.pm/packages/commanded_extreme_adapter)
---
## v0.14.0
### Enhancements
- Dispatch command with `:eventual` or `:strong` consistency guarantee ([#82](https://github.com/commanded/commanded/issues/82)).
- Additional stream prefix per aggregate ([#77](https://github.com/commanded/commanded/issues/77)).
- Include custom metadata during command dispatch ([#61](https://github.com/commanded/commanded/issues/61)).
- Validate command dispatch registration in router ([59](https://github.com/commanded/commanded/issues/59)).
### Upgrading
Please ensure you upgrade the following event store dependencies.
Using the Elixir [EventStore](https://github.com/commanded/eventstore):
- `eventstore` to [v0.11.0](https://hex.pm/packages/eventstore)
- `commanded_eventstore_adapter` to [v0.2.0](https://hex.pm/packages/commanded_eventstore_adapter)
Using Greg's [Event Store](https://eventstore.org/):
- `commanded_extreme_adapter` to [v0.3.0](https://hex.pm/packages/commanded_extreme_adapter)
---
## v0.13.0
### Enhancements
- Command dispatch optionally returns aggregate version, using `include_aggregate_version: true` during dispatch.
---
## v0.12.0
### Enhancements
- `Commanded.Event.Handler` and `Commanded.ProcessManagers.ProcessManager` macros to simplify defining, and starting, event handlers and process managers. Note the previous approach to defining and starting may still be used, so this is *not* a breaking change.
---
## v0.11.0
### Enhancements
- Shutdown idle aggregate processes ([#43](https://github.com/commanded/commanded/issues/43)).
---
## v0.10.0
### Enhancements
- Extract event store integration to a behaviour (`Commanded.EventStore`). This defines the contract to be implemented by an event store adapter. It allows additional event store databases to be used with Commanded.
By default, a `GenServer` in-memory event store adapter is used. This should **only be used for testing** as there is no persistence.
The existing PostgreSQL-based [eventstore](https://github.com/commanded/eventstore) integration has been extracted as a separate package ([commanded_eventstore_adapter](https://github.com/commanded/commanded-eventstore-adapter)). There is also a new adapter for Greg Young's Event Store using the Extreme library ([commanded_extreme_adapter](https://github.com/commanded/commanded-extreme-adapter)).
You must install the required event store adapter package and update your environment configuration to specify the `:event_store_adapter` module. See the [README](https://github.com/commanded/commanded/blob/master/README.md) for details.
---
## v0.9.0
### Enhancements
- Stream events from event store when rebuilding aggregate state.
---
## v0.8.5
### Enhancements
- Upgrade to Elixir 1.4 and remove compiler warnings.
## v0.8.4
### Enhancements
- Event handler and process manager subscriptions should be created from a given stream position ([#14](https://github.com/commanded/commanded/issues/14)).
- Stop process manager instance after reaching its final state ([#24](https://github.com/commanded/commanded/issues/24)).
## v0.8.3
### Enhancements
- Middleware `after_failure` callback is executed even when a middleware halts execution.
## v0.8.2
### Bug fixes
- JsonSerializer should ensure event type atom exists when deserializing ([#28](https://github.com/commanded/commanded/issues/28)).
## v0.8.1
### Enhancements
- Command handlers should be optional by default ([#30](https://github.com/commanded/commanded/issues/30)).
## v0.8.0
### Enhancements
- Simplify aggregates and process managers ([#31](https://github.com/commanded/commanded/issues/31)).
---
## v0.7.1
### Bug fixes
- Restarting aggregate process should load all events from its stream in batches. The Event Store read stream default limit is 1,000 events.
## v0.7.0
### Enhancements
- Command handling middleware allows a command router to define middleware modules that are executed before, and after success or failure of each command dispatch ([#12](https://github.com/commanded/commanded/issues/12)).
---
## v0.6.3
### Enhancements
- Process manager instance processes event non-blocking to prevent timeout during event processing and any command dispatching. It persists last seen event id to ensure events are handled only once.
## v0.6.2
### Enhancements
- Command dispatch timeout. Allow a `timeout` value to be configured during command registration or dispatch. This overrides the default timeout of 5 seconds. The same as the default `GenServer` call timeout.
### Bug fixes
- Fix pending aggregates restarts: supervisor restarts aggregate process but it cannot accept commands ([#22](https://github.com/commanded/commanded/pull/22)).
## v0.6.1
### Enhancements
- Upgrade `eventstore` mix dependency to v0.6.0 to use support for recorded events created_at as `NaiveDateTime`.
## v0.6.0
### Enhancements
- Confirm receipt of events in event handler and process manager router ([#19](https://github.com/commanded/commanded/pull/19)).
- Convert keys to atoms when decoding JSON using Poison decoder.
- Prefix process manager instance snapshot uuid with process manager name.
- Multi command dispatch registration in router ([#16](https://github.com/commanded/commanded/issues/16)).
---
## v0.5.0
### Enhancements
- Include event metadata as second argument to event handlers. An event handler must now implement the `Commanded.Event.Handler` behaviour consisting of a single `handle_event/2` function.
---
## v0.4.0
### Enhancements
- Macro to assist with building process managers ([README](https://github.com/commanded/commanded/tree/feature/process-manager-macro#process-managers)).
---
## v0.3.1
### Enhancements
- Include unit test event assertion function: `assert_receive_event/2` ([#13](https://github.com/commanded/commanded/pull/13)).
- Include top level application in mix config.
## v0.3.0
### Enhancements
- Don't persist an aggregate's pending events when executing a command returns an error ([#10](https://github.com/commanded/commanded/pull/10)).
### Bug fixes
- Ensure an aggregate's pending events are persisted in the order they were applied.
---
## v0.2.1
### Enhancements
- Support integer, atom or strings as an aggregate UUID ([#7](https://github.com/commanded/commanded/pull/7)).
## v0.1.0
Initial release.
